A rare case of pure testosterone-secreting adrenal adenoma in a postmenopausal elderly woman

Background Hyperandrogenemia is more common in puberty and reproductive age, but relatively rare in postmenopausal women. Postmenopausal virilization may result from androgen-producing tumors. Androgen-secreting adrenal tumors are rare in clinical practice and are diagnosed as adrenocortical carcinoma, most of which can co-secrete androgen and cortisol. Highly elevated serum testosterone level with normal adrenal androgens such as dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS) and androstenedione is usually regarded as ovary origin. Here we describe an unusual case of a postmenopausal woman with markedly elevated serum testosterone level, while DHEAS, androstenedione, 17-hydroxyprogesterone and cortisol were within the normal range. Case presentation A 67-year-old postmenopausal woman with hirsutism in the upper lip and armpit, accompanied by clitoromegaly for 5 months. Hormonal evaluation showed markedly elevated serum testosterone level (714.8 ng/ml), whereas DHEAS, androstenedione, 17-hydroxyprogesterone, and cortisol were within the normal range. Imaging examination showed a mass of 1.5 cm in diameter in the left adrenal gland and normal appearance of both ovaries. PET-CT indicated that it was a case of benign adrenal adenoma and excluded ovarian abnormalities and other ectopic tumors. Thus, a pure testosterone-secreting adrenal tumor was suspected and then adrenalectomy was performed. Histology and immunohistochemistry furtherly confirmed the benign adrenocortical adenoma with immunohistochemistry positive for inhibin α, melan A, β-captenin, SYN (focal), Ki-67(< 3%), and negative for chromogranin (CgA), cytokeratin (CK), S-100, P53. After surgery, the level of testosterone returned to normal range and the clinical symptoms also subsided. Conclusions Pure testosterone-secreting adrenal adenomas are extremely rare, but it can induce severe hyperandrogenism and virilization. The source identification of hyperandrogenemia only based on the levels of testosterone, DHEAS and androstenedione is limited. It is important to evaluate not only ovaries but also adrenals in all women with virilization particularly during menopause, even their androstenedione, DHEA and DHEAS level are normal.